1. Technical Field
The present invention relates to a display panel module incorporating a display panel and an illuminating device, a display unit incorporating the display panel module, an inspection device for the display panel and an inspection method for the display panel.
2. Related Art
On manufacturing lines for liquid crystal display panels such as TFT panels, various inspections are conducted for each liquid crystal display panel to detect a defect. In an ordinary inspection, an illuminating device has been used to irradiate a light to an object to be inspected, and a checker visually observes a front surface of the object to mainly inspect for particle residues on the liquid crystal display panel or breaks in electrode wiring (see, for example, JP-A-2000-206001).
However, since the inspection disclosed in the publication is arranged such that the illuminating device irradiates a light to the front surface of the liquid crystal display panel and the checker inspects for defects using the reflection light, the inspection can be capable of detecting defects such as particle residues and breaks in electrode wiring but is incapable of detecting defects such as luminescent spots, which may occur when an image is displayed on the liquid crystal display panel by a transmissive illumination irradiated by a backlight.
Hence, the defects such as luminescent spots have been inspected typically by driving the liquid crystal display panel with the backlight or an inspection illumination kept on. In such a luminescent spot defect inspection, light-transmitting sections (dots) of the liquid crystal display panel are shielded to display the entire black screen so as to detect a luminescent spot defect through a judgment in a visual observation by the checker or by using CCD cameras.
However, the backlight or the inspection illumination is not controlled depending on inspection purposes but merely keeps irradiating a white light of typical luminance, so that the ordinary inspections have difficulty in detecting some types of defects, thus decreasing defect detection accuracy.